Entity.Traits
When a run is executed a set of binary files is created in a 'database' folder under the results directory (see Physical Architecture). These files are collectively called the Results database, and their internal structure reflects EMarket's Entity.Trait data model. This model captures EMarket's approach to data handling in which objects of interest - such as Generators or Nodes - are called entities, and the values describing an entity are its traits (e.g. Nodal Price or Generator Name).
An entity is a logical concept that represents a 'thing' about which EMarket needs to keep data. Things with similar modelling characteristics are classed under the same Entity type. In other words, Entities are typed by the object they represent in the 'modelled' world (e.g. 'Node' or 'Generator'). Different objects of the same entity type are called instances of the entity. So, for example, ABY and TKU are instances of the entity type: Node.
The characteristics describing an entity are its traits. In data handling terms it is the traits that differentiate Instances of the same entity type. The trait 'Node.Name', for example, differentiates the 'ABY' Node entity instance from the 'TKU' Node entity instance.
In EMarket entities and traits are given names that can be used to reference specific data items in the Run Definitions and their values in the associated output. Within a Run Definition Entity.Trait references can be used in any data entry field that accepts a formula expression (the Schedule and all Resource editors). The value of these expressions is calculated at run time and may vary significantly from Tick to Tick, especially if the formula refers to traits derived during the previous Tick.
Entity.Traits syntax: <entity>:<name of particular entity>.<trait>
E.g. Reference to the electricity generated by Generator: GEN01 for a specific period would look like this: Generator:GEN01.Generation
Warning: Entity.Trait references are case sensitive.
A complete list of EMarket Entity.Traits can be found in the Entity.Trait List below.
Special cases exist for the following Entity.Trait types:
Offer Band Entity
Offer Band entities must be referred to using the name of the Generator to which the Offers belong, as follows:
<OfferBand>:<Generator name>_<Offer type><Offer Band number>.<Trait>
where Offer type is E, FR, SR for energy, Fast reserve and Slow Reserve respectively.
Global Traits
Global Traits are user-defined variables that extend EMarket's Entity.Trait model. Global traits can be referred to in formulae in a similar manner as entity traits. Global variables can be defined through the:
- Run Window - through the Volatility Matrix, the File Data or MRJD features; or
- Schedule Window
The syntax for referring to Global traits is: Global.<Global variable name>
Demand Elasticity
Demand elasticity is controlled through an internal variable in EMarket. The syntax is: Region:<RegionName>.DemandElast
where RegionName is the name of a Demand Region defined in the Regions Resource Instance.
For example, if NI and SI are regions for your Run, their Demand elasticity might be given in the schedule as:
| Variable | Definition |
| Region:NI.DemandElast | 0.8 |
| Region:SI.DemandElast | 0.2 |
Note: Demand elasticity is defined as a proportion of the usual Demand, so a Demand elasticity setting of 0.8 sets the Demand to 0.8 of its usual value. The PieceWiseLinear function can be used to define the Demand elasticity.
Entity.Trait List
EMarket Entity.Traits are listed below. Traits marked with an asterisk (*) are either currently not used or are not accessible to users. Some traits should also be regarded as "read-only" traits, in the sense that their values are derived within the model and attempts to change the values are ignored. Such traits are indicated by a hashtag (#). Traits marked with a ^ are "static", that is, although their values are user-defined they cannot be altered during a Run.
Node
| Region* | Region name if Node is defined in a Demand Region |
| Injection# | Total MW being injected at Node this Tick |
| Price# | Nodal price in $/MWh this Tick |
| Demand# |